1、Designation: D 2700 07aDesignation: 236/87An American National StandardStandard Test Method forMotor Octane Number of Spark-Ignition Engine Fuel1This standard is issued under the fixed designation D 2700; the number immediately following the designation indicates the year oforiginal adoption or, in
2、the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 T
3、his laboratory test method covers the quantitativedetermination of the knock rating of liquid spark-ignitionengine fuel in terms of Motor octane number except that thistest method may not be applicable to fuel and fuel componentsthat are primarily oxygenates.2The sample fuel is tested in astandardiz
4、ed single cylinder, four-stroke cycle, variable com-pression ratio, carbureted, CFR engine run in accordance witha defined set of operating conditions. The octane number scaleis defined by the volumetric composition of primary referencefuel blends. The sample fuel knock intensity is compared tothat
5、of one or more primary reference fuel blends. The octanenumber of the primary reference fuel blend that matches theknock intensity of the sample fuel establishes the Motor octanenumber.1.2 The octane number scale covers the range from 0 to 120octane number, but this test method has a working range f
6、rom40 to 120 octane number. Typical commercial fuels producedfor automotive spark-ignition engines rate in the 80 to 90Motor octane number range. Typical commercial fuels pro-duced for aviation spark-ignition engines rate in the 98 to 102Motor octane number range. Testing of gasoline blend stocksor
7、other process stream materials can produce ratings at variouslevels throughout the Motor octane number range.1.3 The values of operating conditions are stated in SI unitsand are considered standard. The values in parentheses are thehistorical inch-pounds units. The standardized CFR enginemeasurement
8、s continue to be in inch-pound units only becauseof the extensive and expensive tooling that has been created forthis equipment.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish
9、appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For more specifichazard statements, see Section 8, 13.4.1, 14.5.1, 15.6.1, AnnexA1, A2.2.3.1, A2.2.3.3(6) and (9), A2.3.5, X3.3.7, X4.2.3.1,X4.3.4.1, X4.3.9.3, X4.3.12.4, and X4.5.1.8.2.
10、 Referenced Documents2.1 ASTM Standards:3D 1193 Specification for Reagent WaterD 1744 Test Method for Water in Liquid Petroleum Prod-ucts by Karl Fischer Reagent4D 2268 Test Method for Analysis of High-Purity n-Heptaneand Isooctane by Capillary Gas ChromatographyD 2360 Test Method for Trace Impuriti
11、es in MonocyclicAromatic Hydrocarbons by Gas ChromatographyD2699 Test Method for Research Octane Number ofSpark-Ignition Engine FuelD 2885 Test Method for Determination of Octane Numberof Spark-Ignition Engine Fuels by On-Line Direct Com-parison TechniqueD 3703 Test Method for Peroxide Number of Avi
12、ationTurbine FuelsD 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD 4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD 4814 Specification forAutomotive Spark-Ignition EngineFuelD 58
13、42 Practice for Sampling and Handling of Fuels forVolatility MeasurementE 344 Terminology Relating to Thermometry and Hydrom-etry1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.01 on Combustion
14、Characteristics.Current edition approved March 1, 2007. Published March 2007. Originallyapproved in 1968. Last previous edition approved in 2007 as D 270007.2Research octane number, determined using Test Method D 2699, is a compan-ion method to provide a similar but typically higher octane rating un
15、der milderoperating conditions.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Withdrawn.1*A Summary of Chan
16、ges section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.E 456 Terminology Relating to Quality and StatisticsE 542 Practice for Calibration of Laboratory VolumetricApparatus2.2 ANSI Standard:5C-3
17、9.1 Requirements for Electrical Analog Indicating In-struments2.3 Energy Institute Standard:IP 224/02 Determination of Low Lead Content of LightPetroleum Distillates by Dithizone Extraction and Colo-rimetric Method63. Terminology3.1 Definitions:3.1.1 accepted reference value, na value that serves as
18、 anagreed-upon reference for comparison, and which is derivedas: (1) a theoretical or established value, based on scientificprinciples, (2) an assigned or certified value, based on experi-mental work of some national or international organization, or(3) a consensus or certified value, based on colla
19、borativeexperimental work under the auspices of a scientific orengineering group. E 4563.1.1.1 DiscussionIn the context of this test method,accepted reference value is understood to apply to the Motoroctane number of specific reference materials determinedempirically under reproducibility conditions
20、 by the NationalExchange Group or another recognized exchange testing orga-nization.3.1.2 Check Fuel, nfor quality control testing, a spark-ignition engine fuel of selected characteristics having an octanenumber accepted reference value (O.N.ARV) determined byround-robin testing under reproducibilit
21、y conditions.3.1.3 cylinder height, nfor the CFR engine, the relativevertical position of the engine cylinder with respect to thepiston at top dead center (tdc) or the top machined surface ofthe crankcase.3.1.4 detonation meter, nfor knock testing, the signalconditioning instrumentation that accepts
22、 the electrical signalfrom the detonation pickup and provides an output signal fordisplay.3.1.5 detonation pickup, nfor knock testing,amagnetostrictive-type transducer that threads into the enginecylinder and is exposed to combustion chamber pressure toprovide an electrical signal that is proportion
23、al to the rate-of-change of cylinder pressure.3.1.6 dial indicator reading, nfor the CFR engine,anumerical indication of cylinder height, in thousandths of aninch, indexed to a basic setting at a prescribed compressionpressure when the engine is motored.3.1.7 digital counter reading, nfor the CFR en
24、gine,anumerical indication of cylinder height, indexed to a basicsetting at a prescribed compression pressure when the engine ismotored.3.1.8 dynamic fuel level, nfor knock testing, test proce-dure in which the fuel-air ratio for maximum knock intensityfor sample and reference fuels is determined us
25、ing the fallinglevel technique that changes carburetor fuel level from a highor rich mixture condition to a low or lean mixture condition, ata constant rate, causing knock intensity to rise to a maximumand then decrease, thus permitting observation of the maxi-mum knockmeter reading.3.1.9 equilibriu
26、m fuel level, nfor knock testing, test pro-cedure in which the fuel-air ratio for maximum knock intensityfor sample and reference fuels is determined by makingincremental step changes in carburetor fuel level, observing theequilibrium knock intensity for each step, and selecting thelevel which produ
27、ces the highest knock intensity reading.3.1.10 firing, nfor the CFR engine, operation of the CFRengine with fuel and ignition.3.1.11 fuel-air ratio for maximum knock intensity, nforknock testing, that proportion of fuel to air that produces thehighest knock intensity for each fuel in the knock testi
28、ng unit,provided this occurs within specified carburetor fuel levellimits.3.1.12 guide tables, nfor knock testing, the specific rela-tionship between cylinder height (compression ratio) andoctane number at standard knock intensity for specific primaryreference fuel blends tested at standard or other
29、 specifiedbarometric pressure.3.1.13 knock, nin a spark-ignition engine, abnormal com-bustion, often producing audible sound, caused by autoignitionof the air/fuel mixture. D 41753.1.14 knock intensity, nfor knock testing, a measure ofthe level of knock.3.1.15 knockmeter, nfor knock testing,the0to10
30、0division indicating meter that displays the knock intensitysignal from the detonation meter.3.1.16 motoring, nfor the CFR engine, operation of theCFR engine without fuel and with the ignition shut off.3.1.17 motor octane number, nfor spark-ignition enginefuel, the numerical rating of knock resistan
31、ce obtained bycomparison of its knock intensity with that of primary refer-ence fuels when both are tested in a standardized CFR engineoperating under the conditions specified in this test method.3.1.18 octane number, nfor spark-ignition engine fuel,any one of several numerical indicators of resista
32、nce to knockobtained by comparison with reference fuels in standardizedengine or vehicle tests. D 41753.1.19 oxygenate, nan oxygen-containing organic com-pound, which may be used as a fuel or fuel supplement, forexample, various alcohols and ethers. D 41753.1.20 primary reference fuel blends above 1
33、00 octane,nthe millilitres per U.S. gallon of tetraethyllead in isooctanethat define octane numbers above 100 in accordance with anempirically determined relationship.3.1.21 primary reference fuels, nfor knock testing, isooc-tane, n-heptane, volumetrically proportioned mixtures of isooc-tane with n-
34、heptane, or blends of tetraetyllead in isooctane thatdefine the octane number scale.3.1.22 primary reference fuel blends below 100 octane,nthe volume percent of isooctane in a blend with n-heptanethat defines the octane number of the blend, isooctane beingassigned as 100 and n-heptane as zero octane
35、 number.5Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.6Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K., http:/www.energyinst.org.uk.D 2700 07a23.1.23 repeatability conditions, nconditions whe
36、re inde-pendent test results are obtained with the same method onidentical test items in the same laboratory by the same operatorusing the same equipment within short intervals of time.E 4563.1.23.1 DiscussionIn the context of this test method, ashort time interval between two ratings on a sample fu
37、el isunderstood to be not less than the time to obtain at least onerating on another sample fuel between them but not so long asto permit any significant change in the sample fuel, testequipment, or environment.3.1.24 reproducibility conditions, nconditions where testresults are obtained with the sa
38、me method on identical testitems in different laboratories with different operators usingdifferent equipment. E 4563.1.25 spread, nin knock measurement, the sensitivity ofthe detonation meter expressed in knockmeter divisions peroctane number.3.1.26 standard knock intensity, nfor knock testing, that
39、level of knock established when a primary reference fuel blendof specific octane number is used in the knock testing unit atmaximum knock intensity fuel-air ratio, with the cylinderheight (dial indicator or digital counter reading) set to theprescribed guide table value. The detonation meter is adju
40、stedto produce a knockmeter reading of 50 for these conditions.3.1.27 toluene standardization fuels, nfor knock testing,those volumetrically proportioned blends of two or more of thefollowing: reference fuel grade toluene, n-heptane, and isooc-tane that have prescribed rating tolerances for O.N.ARVd
41、eter-mined by round-robin testing under reproducibility conditions.3.2 Abbreviations:3.2.1 ARVaccepted reference value3.2.2 C.R.compression ratio3.2.3 IATintake air temperature3.2.4 K.I.knock intensity3.2.5 MIXTmixture temperature3.2.6 O.N.octane number3.2.7 PRFprimary reference fuel3.2.8 RTDresista
42、nce thermometer device (TerminologyE 344), platinum type3.2.9 TSFtoluene standardization fuel4. Summary of Test Method4.1 The Motor O.N. of a spark-ignition engine fuel isdetermined using a standard test engine and operating condi-tions to compare its knock characteristic with those of PRFblends of
43、known O.N. Compression ratio and fuel-air ratio areadjusted to produce standard K.I. for the sample fuel, asmeasured by a specific electronic detonation meter instrumentsystem. A standard K.I. guide table relates engine C.R. to O.N.level for this specific method. The fuel-air ratio for the samplefue
44、l and each of the PRF blends is adjusted to maximize K.I.for each fuel.4.1.1 The fuel-air ratio for maximum K.I. may be obtained(1) by making incremental step changes in mixture strength,observing the equilibrium K.I. value for each step, and thenselecting the condition which maximizes the reading o
45、r (2)bypicking the maximum K.I. as the mixture strength is changedfrom either rich-to-lean or lean-to-rich at a constant rate.4.2 Bracketing ProceduresThe engine is calibrated tooperate at standard K.I. in accordance with the guide table. Thefuel-air ratio of the sample fuel is adjusted to maximize
46、theK.I., and then the cylinder height is adjusted so that standardK.I. is achieved. Without changing cylinder height, two PRFsare selected such that, at their fuel-air ratio for maximum K.I.,one knocks harder (higher K.I.) and the other softer (lowerK.I.) than the sample fuel. A second set of K.I. m
47、easurementsfor sample fuel and reference fuels is required, and the samplefuel O.N. is calculated by interpolation in proportion to thedifferences in average K.I. readings. A final condition requiresthat the cylinder height used shall be within prescribed limitsaround the guide table value for the c
48、alculated O.N. Bracketingprocedure ratings may be determined using either the equilib-rium fuel level or dynamic fuel level approach.4.3 C.R. ProcedureA calibration is performed to establishstandard K.I. using the cylinder height specified by the guidetable for the O.N. of the selected PRF. The fuel
49、-air ratio of thesample fuel is adjusted to maximize the K.I. under equilibriumconditions; the cylinder height is adjusted so that standard K.I.is achieved. The calibration is reconfirmed and the sample fuelrating is repeated to establish the proper conditions a secondtime. The average cylinder height reading for the sample fuel,compensated for barometric pressure, is converted directly toO.N. using the guide table. A final condition for the ratingrequires that the sample fuel O.N. be within prescribed limitsaround that of the O.N. of the sing
